Not worth the $$$
I'm not sure if it was because we anticipated too much on this activity and expected more, but I can say I would go out on the Honolulu screamer before I'd pay half the price for the sub trip again.
The 1st time was in 2004, and everyone was disappointed that we rarely saw any fish and only got a quick glimspe of a stingray. The sub was very cramped. The AC helped but it still felt stuffy. We were told that its rare not to see any fish, so we tried it again in 2007. And only because our children begged us to go (since they didnt come with us in 04)
But, same thing..Murky water, hardly any fish, one turtle sighting that lasted about 8 secs. And from experience, I can assure you if youre not within the 1st group of people abroad, you will not get a window seat (just in case you get lucky enough to see anything)
Simply put...children will love it. You however will get bored, and actually look forward for the trip to end. Even if they took you to marine-life paradise, its not worth the price, which is the key reason, I'm so harsh and writing such a long review.
Try a catamaran (not the ones charging $50 a person though) The Honolulu screamer was a blast as well. If wanna see fish go to the aquarium or snorkling. Just dont say I didnt warn ya on the sub though :)